Gathering information through periodic or continuous measurement in the field to provide a view of current conditions. In some instances, observations may not be subject to rigorous review before release; this will be noted in the documentation accompanying the data.

Information on world earthquake activity with links to facts and lists on large earthquakes, earthquake e-mail notification, hazards and preparedness, educational links, news and highlights and other seismic information.

Lead page for detailed United States surface water information with links to real-time and historic streamflow data, suspended sediment data, USGS programs and facilities, publications, techniques, and featured news releases.